Personal portable apparatus for use in completing a telephone call

ABSTRACT

An improvement in the transparency of personal telecommunications over the prior art is achieved by automatically placing a return call from a personal communications unit of a called individual in response to a call from a caller and alerting the called individual to the existence of the call placed to his personal number only upon an indication that the call from the calling telephone remains in progress. In one embodiment of the invention, the called individual associates his personal communications unit with a telephone channel, before his reception of any calls. Should a caller make a call to the called individual&#39;s personal calling number, the telephone network causes the transmission of an actuation signal. In response to the actuation signal, the personal communications unit places a call to a predetermined number over a switched telephone network using the aforementioned associated telephone channel. As long as the telephone network determines that the caller&#39;s telephone call continues to be in progress, it sends an “in progress” signal over the telephone channel to the personal communications unit. During continued reception of the in-progress signal, the personal communications unit causes the generation of an alerting indication. A going off-hook on the telephone channel by a telephone during alerting results in completion of the caller&#39;s telephone call to the seizing telephone. To this end, the telephone network stops sending the in progress signal and bridges the caller&#39;s call to the return call placed by the personal communications unit.

TECHNICAL FIELD

This invention relates to personal communications and, moreparticularly, to systems for setting up communications between a callerand a called individual using a combination of paging and call bridging.

BACKGROUND OF THE INVENTION

A problem with setting up telecommunications connections today is thedifficulty of locating called individuals who are highly mobile. Thisproblem is partially alleviated by mobile telephone technology and radiopaging systems. However, a caller typically must place several calls toreach a particular individual, one call to each particular type ofcommunication system of which that individual is a subscriber.

A particular prior art approach to reducing the number of callsnecessary to reach an individual have combined: a) telephone numbersassigned to individuals rather than locations (personal telephonenumbers), b) incoming call management techniques, c) radio pagingtechnology and d) mobile telephone technology. More particularly, theprior art system 1) receives a call from a caller to the personal numberof a called individual, 2) places the received call on hold, 3) pagesthe called individual, and 4) connects the caller to the calledindividual if the latter places a return call to a predetermined number.See the commonly-assigned copending U. S. patent application Ser. No.07/667,734, filed Mar. 11, 1991. A call established by this type ofsystem is not transparent to the called individual, i.e., the calledindividual perceives the reception of such a call differently from thereception of an ordinary telephone call. This is because the calledindividual must locate a telephone upon receipt of the page and,thereafter, take the action of making the return call. Moreover, thecaller may have ended the call, i.e., decided to “hang up”, by the timethe called individual completes the return call. In this case, thecalled individual may become confused as he determines that he has madethe return call in vain.

SUMMARY OF THE INVENTION

An improvement in the transparency of personal telecommunications overthe prior art is achieved, in accordance with the principles of theinvention, by automatically placing a return call from a personalcommunications unit of a called individual in response to a call from acaller and alerting the called individual to the existence of the callplaced to his personal number only upon an indication that the call fromthe calling telephone remains in progress. This overcomes the potentialdrawbacks of the prior art system because it assures the calledindividual that he will be connected to a call that continues to existwhen the personal communications unit alerts.

In one embodiment of the invention, the called individual associates hispersonal communications unit with a telephone channel, before hisreception of any calls. Should a caller make a call to the calledindividual's personal calling number, the telephone network causes thetransmission of an actuation signal to the personal communications unit.In response to the actuation signal, the personal communications unitplaces a return call over a switched telephone network to apredetermined number using the aforementioned telephone channel. As longas the telephone network determines that the caller's telephone callcontinues to be in progress, it sends a so-called “in progress” signalover the telephone channel to the personal communications unit. Afterthe initial receipt of the in-progress signal, and during its continuedreception, the personal communications unit causes the generation of analerting indication that a person can perceive. A going off-hook on thetelephone channel by a telephone during the generation of the alertingindication results in completion of the caller's telephone call to theoff-hook telephone. To this end, the telephone network stops sending thein progress signal and bridges the caller's call to the return callplaced by the personal communications unit. Advantageously, unless thecalled individual receives a call, the telephone channel remains freefor the placing and receiving of telephone calls, as if it remainedunassociated with the personal communications unit.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 shows an arrangement for providing transparent personaltelecommunications services, in accordance with the principles of theinvention;

FIG. 2 shows, in block diagram form, a more detailed view of a personalcommunications unit shown in FIG. 1;

FIG. 3 shows an expanded view of a wired line control unit shown in FIG.2;

FIG. 4 shows, in block diagram form, an expanded view of the bridgingand signaling unit shown in FIG. 1;

FIGS. 5 and 6, when connected together, show a flow chart of anexemplary process for completing a call placed to the personal number ofan individual associated with the personal communications unit shown inFIG. 1;

FIG. 7 shows another embodiment of the invention in which a personalcommunications unit is combined with a mobile telephone to form aportable personal communications unit; and

FIG. 8 shows, in simplified block diagram form, an expanded version ofthe portable personal communications unit shown in FIG. 7.

DETAILED DESCRIPTION

FIG. 1 shows arrangement 100 for providing transparent personaltelecommunications services, in accordance with the principles of theinvention. A caller places a call from calling telephone 101 to thepersonal telephone number of an individual associated with personalcommunications unit 103. The caller's call passes over telephone line105 to central office 107. Central office 107, in turn, routes the callto bridging and signaling unit 109, which is associated with the callednumber. Personal communications unit 103 is also associated with thecalled personal telephone number, as discussed further below.

Current United States telephone practices generally require that atleast the one local exchange carrier (LEC), containing central office107, routes the caller's call. Also, the caller's call may be routed viaan inter-exchange carrier, represented by toll switch 111, and anotherlocal exchange carrier, represented by central office 113. Centraloffices 107 and 113 may be the same office. If so, the call would notpass through any inter-exchange carrier or any other central offices.

Bridging and signaling unit 109 contains a so-called meet-me bridge forconnecting at least two incoming calls to each other. Upon receipt ofthe caller's call, bridging and signaling unit 109 forwards paginginformation to paging node 115. The paging information includes apredetermined code that uniquely identifies the called individual'spersonal communications unit 103 and a telephone number to which areturn call must be placed, in order to connect with or “meet” thecaller. A copy of the predetermined code is stored within personalcommunications unit 103. Also, the telephone number for the return callis reserved, in advance, for use by bridging and signaling unit 109. Itsselection is described further below. Paging node 115 causes a pagingsignal containing the paging information to be broadcast from pagingtower 119. Paging systems are well known in the art.

In accordance with an aspect of the invention, the telephone number ofthe return call is typically a toll-free, e.g., 800-type, of telephonenumber. One advantage of using an 800-type of telephone number is thatthe cost of the return call will not be charged to the subscriber oftelephone line 117, who often will not be the called individual. Nocharge is incurred because 800-type telephone numbers are so-called“toll-free” telephone numbers. The owner of the “toll-free” telephonenumber, rather than the subscriber of the telephone line over which thecall is made, incurs the charge for calls to such a number. Anotheradvantage of using an 800-type of telephone number is that it allowspersonal communications allows unit 103 to place the return call withouthaving any information about the area code of the telephone line towhich it is connected. This is because calls to 800-type telephonenumbers are unlike calls to conventional telephone numbers. Calls toconventional telephone numbers employ the area code for routingpurposes. Such calls require the explicit dialing of the area code ofthe destination location for calls placed from one area code to anotherand that no area code be dialed for calls placed within a single areacode. However, 800-type telephone numbers employ the 800 area code toindicate the toll-free nature of the call and that the telephone networkshould translate the telephone number to its corresponding destinationlocation. As such, the 800 area code must always be dialed for suchcalls to give these indictions to the telephone network, even if thedestination location is within the same area code as the location of thecaller.

Telephone line 117 connects personal communications unit 103 to centraloffice 121. Telephone mounting cord 123 connects personal communicationsunit 103 to telephone 125. Standard telephone RJ-11 jacks 127 and 129respectively connect telephone line 117 and telephone mounting cord 123to personal communications unit 103. Again, the individual associatedwith personal communications unit 103 need not be, and typically is not,the owner of telephone 125 or the subscriber of telephone line 117.Instead, it is expected that each owner of a personal communicationsunit 103 will take it with him in his travels and attach it, in themanner shown, at each of his destinations, so as to receive calls.

Personal communications unit 103 receives paging signals transmittedfrom paging tower 119. In the event that the code contained within thepaging information of a paging signal matches the predetermined codestored in personal communications unit 103, personal communications unit103 automatically places a telephone call, which is the return call, tothe telephone number specified in that page, over a switched telephonenetwork, in accordance with an aspect of the invention. As such, centraloffice 121 receives the return call, from telephone line 117, and routesit to bridging and signaling unit 109. To this end, central office 121may route the call via an inter-exchange carrier, represented by tollswitch 133, and another local exchange carrier, represented by centraloffice 113. The routing of return calls to 800-type telephone numbersfollows well-known practices in the art for routing calls to 800-typetelephone numbers. U.S. Pat. No. 4,191,860 issued to R. P. Weber on Mar.4, 1980, describes one system for routing and translating 800-typenumbers. The association of central office 121 with database 135 andtoll switch 133 with database 137 aids in the routing process.

In accordance with the principles of the invention, personalcommunications unit 103 alerts the called individual to the existence ofa call placed to his personal number only upon an indication that thecall from calling telephone 101 remains in progress. To this end, uponreceipt of the return call, bridging and signaling unit 109 continuallydetermines if the call from telephone 101 remains in progress. As longas the call from telephone 101 remains in progress, bridging andsignaling unit 109 sends a so-called “in-progress” signal, over thereturn call, to personal communications unit 103. Personalcommunications unit 103 begins to alert upon receipt of the in-progresssignal. Furthermore, in accordance with an aspect of the invention,personal communications unit 103 continues to alert only duringcontinued reception of the in-progress signal or until it detectstelephone 125 having gone off-hook while personal communications unit103 was still alerting. To complete the caller's call, in accordancewith aspects of the invention, personal communications unit 103 connectstelephone 125 to telephone line 117 if telephone 125 goes off-hook whilepersonal communications unit 103 is alerting. At that time, bridging andsignaling unit 109 connects the caller's call from telephone 101 to thereturn call. As a result of these connections, the caller at telephone101 can converse with the called individual at telephone 125.

FIG. 2 shows, in block diagram form, a more detailed view of personalcommunications unit 103. Page receiver 201 receives paging signalstransmitted from paging tower 119 via paging antenna 203. Page receiver201 also stores the predetermined code associating an individual withpersonal communications unit 103. In response to the reception of apaging signal containing paging information having this code, pagereceiver 201 sends to control unit 205, over link 207, the telephonenumber to which personal communications unit 103 must place the returncall. As noted, this telephone number is also part of the paginginformation. Upon receiving the telephone number for a return call,control unit 205 cooperates with wire line control 209 to place thereturn call to the received telephone number, if telephone line 117 isidle. To this end, control unit 205 and wire line control 209communicate over bi-directional link 211.

In accordance with an aspect of the invention, if the return call issuccessfully placed and personal communications unit 103 receives anin-progress signal indicating that the callers telephone call continuesto be in progress, control unit 205 signals call alert 213, over link215, to begin generating an alerting indication. In one embodiment, thealerting indication is a predetermined beeping tone. Also, control unit205 supplies to optional display 131, over link 217, the identity of thecaller, if that information is available. Either a portion of the pagingsignal or signals supplied via telephone line 117 may provide the calleridentity.

FIG. 3 shows an expanded view of wired line control 209. The elements ofwired line control 209 include: a) relay 301, b) current detector (I)303, c) dual tone multi-frequency (DTMF) sender 305 and d) in-bandsignaling unit 307. All of the elements respond to commands from controlunit 205. They receive such commands over link 211. Relay 301 isolatestelephone 125 from line 117 while the automatic placing of a return callproceeds. Otherwise, the contacts of relay 301 remain closed. Currentdetector 303 determines if loop current is flowing from telephone line117 to telephone 125. The flowing of loop current indicates thattelephone 125 is either in an off-hook state or ringing. In either case,telephone 125 and telephone line 117 are busy and line 117 isunavailable for use in placing a return call. Current detector 303transmits the results of its determination to control unit 205, via link211. DTMF sender 305 can both take telephone line 117 off-hook and sendDTMF tones over telephone line 117 to the central office. In-bandsignaling unit 307 receives signals from telephone line 117. It informscontrol unit 205 of the signals it receives over link 211. In-bandsignaling unit 307 can also send in-band signals over telephone line 117to central office 121.

FIG. 4 shows, in block diagram form, an expanded view of bridging andsignaling unit 109. Bridging and signaling unit 109 includes: a) trunkinterfaces 401, b) DTMF receivers 403, c) bridge control 405, d) voiceamplifier and ringback units 407, e) switch fabric 409, f) in-bandsignaling unit 411 and g) trunk interfaces 413. Bridge control 405controls and coordinates the operation of bridging and signaling unit109 by communicating commands and information over control bus 417.

Calls placed by callers to personal numbers of individuals associatedwith a personal communications unit 103 are received and terminated atbridging and signaling unit 109 by one of trunk interfaces 401. In oneembodiment, the interface between central office 113 and trunkinterfaces 401 is the same type of interface employed to connect acentral office to a PBX equipped for direct inward dialing (DID). Aspart of terminating a call, central office 113 sends the last fourdigits of the personal telephone number to bridging and signaling unit109 over the trunk. These digits are sent as DTMF signals. One of DTMFreceivers 403 receives the DTMF signals over one of lines 415 anddecodes them. It informs bridge control 405 at which of trunk interfaces401 the call arrived and the decoded four digits.

In response to the reception of the four decoded digits, bridge control405 instructs one of voice amplifier and audible ring units 407 tosupply ringback tone over the one of trunk interfaces 401 at which thecall arrived. However, answer supervision is not supplied so that,advantageously, the caller is not charged for the call until it isanswered by the called party. Bridge control 405 contains memory 419.Memory 419 maps the received four digits of the called individual'spersonal telephone number to the predetermined code stored in thepersonal communications unit 103 associated with the called individual.Bridge control 405 selects an idle one of trunk interfaces 413 at whichto receive the return call. The trunks connecting central office 113 totrunk interfaces 413 are dedicated trunks and each has its own telephonenumber. Thereafter, bridge control 405 supplies to paging node 115(FIG. 1) both the telephone number of the trunk associated with theselected idle one of trunk interfaces 413, as the number for the returncall, and the predetermined code of the called individual.

Upon receipt of a return call at the selected one of trunk interfaces413, bridge control 405 determines which of trunk interfaces 401 holdsthe call of the caller that corresponds to this return call. Inaccordance with an aspect of the invention, if the caller's call isstill in progress, bridge control 405 causes in-band signaling unit 411to transmit an in-progress signal to personal communications unit 103.If the called individual goes off-hook at telephone 125 (FIG. 1),in-band signaling unit 411 receives a signal from in-band signaling unit307 (FIG. 3) indicating this. In response to this signal, bridge control405 commands switch fabric 409 to interconnect the caller's call withits respective return call. Bridge control 405 also commands therespective one of voice amplifier and ringback units 407 to ceasesupplying ringback tone to the caller and to switch to amplificationmode. This is necessary because a back-to-back connection of twoseparate telephone calls requires amplification to overcome theattendant loss of signal strength. Simultaneously, bridge control 405commands trunk interface 401 to return the well-known answer supervisionsignal to the caller's call.

FIGS. 5 and 6, when connected together, show a flow chart of anexemplary process for completing a call placed to the personal number ofa called individual associated with one of personal communications unit103 (FIG. 1). The process begins in step 501 (FIG. 5) when a callerdecides to make a call to the personal number of the individualassociated with personal communications unit 103. To this end, in step503, the caller dials the called individual's personal number attelephone 101 (FIG. 1). A local exchange carrier (LEC) routes the callto bridging and signaling unit 109 in step 505. Thereafter, in step 507,the LEC supplies the called number and, if available, the calling numberto bridging and signaling unit 109.

In step 509, bridging and signaling unit 109 supplies ringback tone totelephone 101. However, answer supervision is not supplied. Bridging andsignaling unit 109 sends to paging node 115 the paging information,i.e., the predetermined code of the called individual that is storedwithin personal communications unit 103 and the telephone number towhich the return call must be made, in step 511. In step 513, pagingtower 119 broadcasts a paging signal that includes the paginginformation.

Personal communications unit 103 receives the paging signal in step 515.Next, in conditional branch point 517, current detector 303 (FIG. 3)tests to determine if telephone line 117 is idle. If the test result instep 517 is NO, control passes to step 519, which waits for apredetermined amount of time. Control then passes back to step 517, toretest the idle status of telephone line 117. As will be readilyapparent to those skilled in the art, the total length of time waitedfor telephone line 117 to become idle may be limited to a predeterminedperiod of time.

If the test result in step 517 is YES, control passes to step 521, inwhich relay 301 (FIG. 3) opens, causing the disconnection of telephone125 (FIG. 1) from telephone line 117. In step 523, DTMF sender 305 (FIG.3) seizes telephone line 117 by supplying an off-hook indication tocentral office 121. In step 525, in-band signaling unit 307 (FIG. 3)detects the presence of dial tone supplied by central office 121 (FIG.1). Next, in step 527, DTMF sender 305 dials the number for the returncall, e.g., an 800-type telephone number, received as part of the paginginformation. Central office 121 routes the return call to bridging andsignaling unit 109, in step 529. Thereafter, bridging and signaling unit109 tests to determine, in conditional branch point 531, if the caller'scall remains in progress. If the test result in step 531 is NO, bridgingand signaling unit 109 sends a disconnect signal to personalcommunications unit 103. In step 535, personal communications unit 103receives the disconnect signal. Both bridging and signaling unit 109 andpersonal communications unit 125 go on-hook, in step 537. Thereafter,the process is exited in step 539.

If the test result in step 531 is YES, control passes to step 541, inwhich bridging and signaling unit 109 sends an in-progress signal fromin-band signaling unit 411, in accordance with an aspect of theinvention. In step 543, personal communications unit 103 receives thein-progress signal. In accordance with an aspect of the invention,personal communications unit 103 begins alerting, in step 545, inresponse to reception of the in-progress signal. Control next passes toconditional branch point 547, which tests to determine if telephone 125(FIG. 1) has gone off-hook. If the test result in step 547 is NO,control passes to conditional branch point 549, which tests to determineif personal communications unit 103 continues to receive the in-progresssignal. If the test result in step 549 is NO, control passes to step537, and the process continues as described above. If the test result instep 549 is YES, control passes back to step 545 and personalcommunications unit 103 continues to alert.

If the test result in step 547 is YES, control passes to step 551, inwhich personal communications unit 103 sends to bridging and signalingunit 109 an in-band signal indicating that telephone 125 has goneoff-hook. Also, alerting by personal communications unit 103 ceases. Inresponse to the signal indicating that telephone 125 has gone off-hook,bridging and signaling unit 109 stops sending ringback tone to telephone101, in step 553. Next, in step 555, switch fabric 409 (FIG. 4)interconnects the caller's call and the return call at bridging andsignaling unit 109. This allows the caller to talk with the calledindividual. Bridging and signaling unit 109 also causes answersupervision to be supplied over the one of trunk interfaces 401 (FIG. 4)at which the caller's call is terminated. Advantageously, this allowscharging of the caller only for the time that he has a connection foruse in conversing with the called individual. The process is then exitedin step 539.

At the end of the conversation, either the caller or the calledindividual will go on-hook. At that time, the call between the on-hookparty and bridging and signaling unit 109 is taken down. Furthermore,bridging and signaling unit 109 causes the call by the party not goingon-hook to be taken down as well.

FIG. 7 shows another embodiment of the invention in which portablepersonal communications unit 701 is formed by combining personalcommunications unit 103 with a mobile telephone. When hooked-up to awired telephone line and a wired telephone, in the manner shown,operation of portable personal communications unit 701 is the same asoperation of personal communications unit 103. An additional feature ofportable personal communications unit 701 is that if telephone line 117is in use, and, therefore, unavailable for the placing of a return call,the return call is placed by the mobile telephone portion of portablepersonal communications 701 using mobile telephone service. Also,whenever portable personal communications unit 701 is not connected to atelephone line, it places the return call using mobile telephoneservice.

Shown in FIG. 8, in simplified block diagram form, is an expandedversion of portable personal communications unit 701. Page receiver 201,antenna 203, link 207, wire line control 209, link 211, call alert 213,link 215, link 217 and display 131 are the same as described above forpersonal communications unit 103, as shown in FIG. 2. Mobile telephonecontroller 803 controls the mobile telephone functions of portablepersonal communications unit 701. To this end, link 811 connects mobiletelephone controller 803 to radio transceiver 807. Also, link 809connects mobile telephone controller 803 to control unit 205. Controlunit 805 is an enhanced version of control unit 205 (FIG. 2). Theseenhancements include an interface with mobile telephone controller 803that permits the placing of telephone calls using the mobile telephoneservice, in addition to the wired line capability. Implementation ofsuch enhancements will be readily apparent to those skilled in the art.

In accordance with an aspect of the invention, should telephone line 117become available after the placing of a return call over a mobiletelephone channel, the mobile telephone call may be transferred totelephone line 117. To this end, the called individual presses optionalreset button 705 on portable personal communications unit 701. As aresult, portable personal communications unit 701 goes on-hook on themobile telephone channel it was using. Immediately thereafter, portablepersonal communications unit 701 goes off-hook on telephone line 117 andredials the telephone number from the last received paging information.In this embodiment, bridging and signaling unit 109 holds the caller'scall after detecting the end of a return call for a length of timesufficient for a return call over a wired telephone line to be completedbefore it begins disconnecting the caller. As such, it results inrestarting the process shown in FIG. 5 at step 529. Therefore, thesecond return call over the wired telephone line, made in response tothe pressing of reset button 705, will complete a connection to thecaller as described above. Implementing the reverse transfer, from awired telephone to mobile telephone service will be readily apparent tothose skilled in the art

If personal communications unit 103 is placed “behind” a PBX, it may benecessary, as will be well understood by those skilled in the art, forpersonal communications unit 103 to dial a prefix code, e.g., 9, toreach an outside line prior to dialing the telephone number of thereturn call. In such a case, personal communications unit 103 mustobtain and store the necessary prefix code prior to completing anycalls. In one embodiment, the process of obtaining the prefix code bypersonal communications unit 103 employs a training procedure. Forexample, if personal communications unit 103 detects the reception of apredetermined code from telephone 125 when it is off-hook, e.g., **#,any digits received thereafter, until telephone 125 goes on-hook again,are used as the prefix code. Other procedures and techniques fortraining personal communications unit 103 will be readily apparent tothose skilled in the art.

Another application of the invention is the automatic set-up of aconference call. A caller at telephone 101 starts the set-up procedureby placing a call to the number of a conference service. This call isrouted, as described above, to bridging and signaling unit 109, whichcauses multiple paging signals to be broadcast. Each paging signalincludes a respective one of the predetermined codes stored in thepersonal communications unit 103 of the individuals to be included inthe conference. Also, each of the paging signals contains a telephonenumber for a return call. As each of the personal communications unitsthat received a paging signal for the conference makes its return call,bridging and signaling unit 109 conferences the respective return callstogether with the caller's call from telephone 101 at switch fabric 409(FIG. 4).

In another embodiment of the invention, bridging and signaling unit 109always supplies, to paging node 115, the same 800-type telephone numberfor every return call rather than the particular number of the one ofthe trunks terminated by trunk interfaces 413. Central office 121, tollswitch 133 and central office 113 route return calls placed to thisnumber to available ones of trunk interfaces 413. Upon completing thereturn call to the supplied number, personal communications unit 103supplies, via in-band signaling unit 307 (FIG. 3), its predeterminedcode from page receiver 201 (FIG. 2). Bridging and signaling unit 109receives this code via in-band signaling unit 111 and supplies the codeto bridge control 405 (FIG. 4). Bridge control 405, employing memory419, maps the received code to the one of trunk interfaces 401 holdingthe caller's call. If the caller's call is still in progress, in-bandsignaling unit 411 transmits the in-progress signal. Thereafter, theoperation proceeds as described above.

In another embodiment of the invention, trunk interfaces 401 and 413terminate all digital transmission facilities, e.g., T-1 or ISDN primaryrate interfaces (PRI). However, the functionality of trunk interfaces401 and 413, that of receiving, holding, and identifying telephonecalls, remains the same. The design of such trunk interfaces is wellknown in the art Also, such embodiments of the invention can include theprocessing of both in-band and out-of-band signals. To this end, in-bandsignaling units 307 (FIG. 3) and 411 are replaced by in-band or in andout-of-band signaling units. The design of such signaling units will bereadily apparent to those skilled in the art.

One advantage of the embodiment of the invention in which call alert 213(FIG. 2) generates a beeping tone is that a personal telephone callusing personal communications unit 103 (FIG. 1) does not activate ananswering machine bridged with telephone 125. This is typically usefulfor situations in which either the owner of telephone 125 or thesubscriber of telephone line 117 is different from the individualassociated with personal communications unit 103. In such a situation,the person associated with personal communications unit 103 may neverreceive messages left on an answering machine bridged with telephone125.

In another embodiment of the invention, call alert 213 could supply aringing signal to telephone 125. Advantageously, such an arrangementmakes the called individual's perception of such a telephone call thesame as his perception of a typical direct dial telephone call. Also,this could allow for the activation of an answering machine bridged withtelephone 125. In accordance with an aspect of the invention, theringing signal supplied may cause the ringing cadence sounded bytelephone 125, to be distinct from the cadence generated in response toany other type of telephone call telephone 125 receives. In accordancewith another aspect of the invention, if telephone line 117 is in useupon reception of a paging signal, personal communications unit 103 canalert with a further distinctive pattern to indicate a call has beenplaced to the personal telephone number. This serves a purpose similarto that of the call waiting signal used in current telephone systems.

As noted above, display 131 can display the number of the caller ifpersonal communications unit 103 receives the necessary information. Thepaging information may contain the caller's number. Alternatively,bridging and signaling unit 109 may supply the caller's number as partof the in-band signals it supplies from in-band signaling unit 411 (FIG.4). In another embodiment of the invention, in-band signaling unit 307(FIG. 3), of personal communications unit 103, receives and recognizesthe well known incoming call line identification (ICLID) signals.Central offices supply ICLID signals for the service commonly known bythe trade name of CALLER ID. In accordance with a feature of theinvention, detection of the ICLID signals and displaying of thecorresponding number on display 131 occurs regardless of whether theirgeneration resulted from a regular telephone call placed to telephone125 or a return call placed in response to a paging signal.

In a further embodiment of the invention, control unit 805 turns onpower to the mobile telephone portion of portable personalcommunications unit 701 only in response to the reception of paginginformation by a page receiver 201. Until portable personalcommunications unit 701 receives paging information, it remainsunpowered. An advantage of this embodiment is that the mobile telephonedoes not consume power listening to its control channel when calls arenot actually in progress. This tends to increase the period of timebetween recharging cycles.

The foregoing merely illustrates the principles of the inventions. Itwill thus be appreciated that those skilled in the art will be able todevise various arrangements which, although not explicitly described orshown herein, embody the principles of the invention and are thus withinits spirit and scope.

We claim:
 1. Portable apparatus for use in completing a telephone callthat is initiated from a calling telephone to a called individualcomprising: means for receiving an actuation signal in response to saidtelephone call placed to said called individual; means responsive toreception of said actuation signal for placing a second telephone callover a telephone channel through a switched telephone network to apredetermined location; means for receiving from said location over saidtelephone channel an indication that said telephone call from saidcalling telephone continues to be in progress; and means responsive tocontinued reception of said indication for supplying an alertingindication from said portable device.
 2. The invention as defined inclaim 1 wherein said telephone channel is a wired subscriber telephoneline.
 3. The invention as defined in claim 1 wherein said telephonechannel is a mobile subscriber telephone channel.
 4. The invention asdefined in claim 1 wherein said second telephone call to a predeterminedlocation is a toll-free call.
 5. The invention as defined in claim 1wherein said second telephone call to a predetermined location is placedfrom behind a PBX by dialing a prefix code prior to dialing a telephonenumber corresponding to said location.
 6. The invention as defined inclaim 1 further including means for transmitting over said telephonechannel a predetermined code identifying said apparatus.
 7. Theinvention as defined in claim 1 in which said predetermined location isa location to which said calling telephone call has been routed andwherein said apparatus further includes: means for detecting that atelephone associated with said telephone channel went off-hook whilesaid means for supplying said alerting indication was supplying saidalerting indication; and means responsive to said going off-hook forconnecting said telephone associated with said telephone channel to saidtelephone channel, whereby said calling telephone can be connected tosaid telephone associated with said telephone channel via said location.8. The invention as defined in claim 1 further including means forreceiving the telephone number of the calling telephone and fordisplaying that number.
 9. The invention as defined in claim 1 whereinsaid actuation signal is a paging signal.
 10. The invention as definedin claim 1 wherein said location is identified to said apparatus as partof said actuation signal.
 11. The invention as defined in claim 1wherein said means for placing a second telephone call places saidsecond telephone call by always dialing at least the same predeterminedarea code no matter what the area code of said telephone channel overwhich said second telephone call is placed.
 12. The invention as definedin claim 1 wherein said call placing means places said second telephonecall only if said telephone channel is determined to be not alreadyseized when said actuation signal is received.
 13. The invention asdefined in claim 12 further including means responsive to adetermination that said telephone channel is seized upon reception ofsaid actuation signal for supplying a secondary alerting indication. 14.The invention as defined in claim 1 wherein said means for supplying analerting indication directly supplies an alerting signal perceivable bya human being.
 15. The invention as defined in claim 14 wherein saidalerting signal perceivable by a human being is perceptuallydistinguishable from alerting signals generated in response to receptionof calls over said telephone channel.
 16. The invention as defined inclaim 7 wherein said means for supplying an alerting indication suppliesa ringing signal to said telephone.
 17. The invention as defined inclaim 16 wherein said ringing signal causes an alert to be generated bysaid telephone that is perceptually distinguishable from all otheralerts generated by said telephone.
 18. The invention as defined inclaim 1 wherein said telephone channel is a primary telephone channeland including means for determining that said primary telephone channelis seized upon reception of said actuation signal and for causing saidsecond telephone call to be placed over a secondary telephone channelassociated with said apparatus instead of over said primary channel. 19.The invention as defined in claim 18 wherein said primary telephonechannel is a wired subscriber telephone line and said secondarytelephone channel is a mobile telephone channel.
 20. The invention asdefined in claim 1 wherein said telephone channel is a primary telephonechannel and said call placing means can also place calls over asecondary telephone channel and said means for placing a call is alsoresponsive to a reset signal for placing a new call over said primarytelephone channel to said predetermined location to which a precedingcall had been placed over said secondary telephone channel so as toeffect a transfer of said call from said calling telephone to saidprimary telephone channel from said secondary telephone channel.
 21. Theinvention as defined in claim 1 wherein said telephone channel is aprimary telephone channel and said call placing means can also placecalls over a secondary telephone channel and said means for placing acall is also responsive to a reset signal for placing a new call oversaid secondary telephone channel to said predetermined location to whicha preceding call had been placed over said primary telephone channel soas to effect a transfer of said call from said calling telephone to saidsecondary telephone channel from said primary telephone channel.
 22. Theinvention as defined in claim 1 wherein said means for placing saidsecond telephone call includes a mobile telephone and said mobiletelephone remains unpowered until said actuation signal is received.